Import/export .x files in Blender 3.0 (and some earlier versions). The *Poikilos fork* attempts to maintain compatibility with the latest stable Blender and allows install via GUI (Click "Code", "Download ZIP"--See "Install" in readme for the rest of the steps). Related project (also recently updated): https://github.com/ldo/blender-addons-orphaned
Got some troubles while was installing and trying to use it. Was sending some errors, when tried to import X model.